QUESTION:
For all its stability and obstacle avoidance, what if Sojourner were picked
up by a huge gust of wind and landed "flat on its back"? (Sort of like a
turtle on its back.) Is there a way of righting itself again? What if the
batteries have run out and Sojourner is relying on solar power, but because
the panels are then facing the floor, will Sojourner still have enough
reserves to turn itself over?

ANSWER from David Dubov:
The capabilities of the 'Sojourner' rover do not include righting itself if
it is turned over on its solar panel (or back). The hazard avoidance and
mobility capabilities of the vehicle are designed to prevent (during
traverses) an 'overtipping' condition. Although the speed of the winds on
Mars is considerable (estimated to 6m/sec during daytime or 13mi/hr to gusts
of 30m/sec during dust storms or 67mi/hr) the atmosphere is quite thin
(approximately 7mb at the surface of Mars versus 1000mb at sea level on
Earth). There is insufficient atmosphere even in gusting winds to 'pick up'
the rover.